OUString: constify and avoid some temporaries
OUString: constify and avoid some temporaries

Change-Id: Ic5a86644dc0215da5c48c795abb51ee664298d57

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core